1. Field of the Invention
The present invention relates to an endoscope system, and relates in particular to an endoscope system that detects abnormality of an image pickup signal and initializes an image pickup device.
2. Description of the Related Art
Conventionally, an endoscope system including an endoscope, which inserts an elongated endoscope into a body cavity or the like and performs observation of a part to be examined and various kinds of treatment has been widely used. As such an endoscope system, for example, Japanese Patent Application Laid-Open Publication No. 2011-206337 discloses an endoscope system including an electronic endoscope provided with a solid-state image pickup device, and a processor device connected to the electronic endoscope and configured to execute various kinds of signal processing to an image pickup signal from the solid-state image pickup device and perform conversion to image data. Then, the image data converted by the processor device is displayed on a monitor connected to the processor device via a cable.
As the solid-state image pickup device loaded on such an electronic endoscope, a CCD type solid-state image pickup device has been generally used conventionally, however, a CMOS type solid-state image pickup device has been also used in recent years. The CMOS type solid-state image pickup device includes a register for storing setting values (control data) of drive and read operations or the like, and the drive and read operations are performed based on the control data set in the register. The control data is transmitted from the processor device to the electronic endoscope, and set in the register of the CMOS type solid-state image pickup device.
Now, for the endoscope system, sometimes a surgical instrument such as an electrocautery is also used during endoscopic observation, and the control data is sometimes rewritten to an unintended value due to disturbance noise from the electrocautery or the like while the control data is transmitted or after the control data is stored in the register. In this way, in a case that the control data is rewritten due to the disturbance noise or the like, abnormality sometimes occurs in the drive and read operations of the CMOS type solid-state image pickup device.
Therefore, in the endoscope system in Japanese Patent Application Laid-Open Publication No. 2011-206337, the control data stored in the register is superimposed on the image pickup signal outputted from the CMOS type solid-state image pickup device and transmitted to the processor device. Then, the endoscope system, in the processor device, compares the control data superimposed on the image pickup signal with the control data set in the register, and detects whether or not the control data stored in the register is rewritten.
In the case of detecting that the setting value is rewritten, the endoscope system retransmits the control data from the processor device to the CMOS type solid-state image pickup device of the electronic endoscope. That is, in the case of detecting abnormality of the control data stored in the register, normal control data is transmitted to the register of the CMOS type solid-state image pickup device, the control data of the register is reset, and the drive and read operations of the CMOS type solid-state image pickup device are returned to be normal.
In this way, in the case that the control data set in the register of the CMOS type solid-state image pickup device is rewritten to an abnormal value due to influence of the disturbance noise or the like, by setting the normal control data in the register again, the drive and read operations of the CMOS type solid-state image pickup device can be returned to be normal.
In addition, Japanese Patent Application Laid-Open Publication No. 2013-172904 discloses an image pickup apparatus that superimposes a discrimination signal generated by each portion of an image pickup device on an optical black region or a blanking period (blanking region between synchronizing signals) and discriminates an abnormal part based on the signal to which the determination signal of the each portion is added. Thus, in the image pickup apparatus, the abnormal part of the image pickup device is specified in detail.